High speed processing and power saving drive as well as multi-functional processing are requested to electronic devices such as digital computers and transmission devices, and accordingly high speed processing and power saving are also requested to LSIs (Large Scale Integrated circuits) mounted on these electronic devices. To respond to the request of high speed processing, circuits of LSIs are designed by using a circuit driven by a differential signal (differential circuit) instead of a circuit driven by a single end signal (singe end circuit). This is because the differential circuit can operate faster than the single end circuit, so that the differential circuit can reduce skew between input signals.
Therefore, Japanese Laid-open Patent Publication No. 2009-110317 discloses an interface circuit (driver circuit) that can selectively switch between voltage-driven type single end transmission and current-driven type differential transmission by a control signal from outside.